Merge remote-tracking branch 'remotes/philmd-gitlab/tags/edk2-next-20200121' into...
[qemu.git] / ui / vnc-jobs.c
1 /*
2 * QEMU VNC display driver
3 *
4 * Copyright (C) 2006 Anthony Liguori <anthony@codemonkey.ws>
5 * Copyright (C) 2006 Fabrice Bellard
6 * Copyright (C) 2009 Red Hat, Inc
7 * Copyright (C) 2010 Corentin Chary <corentin.chary@gmail.com>
8 *
9 * Permission is hereby granted, free of charge, to any person obtaining a copy
10 * of this software and associated documentation files (the "Software"), to deal
11 * in the Software without restriction, including without limitation the rights
12 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
13 * copies of the Software, and to permit persons to whom the Software is
14 * furnished to do so, subject to the following conditions:
15 *
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
18 *
19 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
24 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
25 * THE SOFTWARE.
26 */
27
28
29 #include "qemu/osdep.h"
30 #include "vnc.h"
31 #include "vnc-jobs.h"
32 #include "qemu/sockets.h"
33 #include "qemu/main-loop.h"
34 #include "block/aio.h"
35
36 /*
37 * Locking:
38 *
39 * There are three levels of locking:
40 * - jobs queue lock: for each operation on the queue (push, pop, isEmpty?)
41 * - VncDisplay global lock: mainly used for framebuffer updates to avoid
42 * screen corruption if the framebuffer is updated
43 * while the worker is doing something.
44 * - VncState::output lock: used to make sure the output buffer is not corrupted
45 * if two threads try to write on it at the same time
46 *
47 * While the VNC worker thread is working, the VncDisplay global lock is held
48 * to avoid screen corruption (this does not block vnc_refresh() because it
49 * uses trylock()) but the output lock is not held because the thread works on
50 * its own output buffer.
51 * When the encoding job is done, the worker thread will hold the output lock
52 * and copy its output buffer in vs->output.
53 */
54
55 struct VncJobQueue {
56 QemuCond cond;
57 QemuMutex mutex;
58 QemuThread thread;
59 bool exit;
60 QTAILQ_HEAD(, VncJob) jobs;
61 };
62
63 typedef struct VncJobQueue VncJobQueue;
64
65 /*
66 * We use a single global queue, but most of the functions are
67 * already reentrant, so we can easily add more than one encoding thread
68 */
69 static VncJobQueue *queue;
70
71 static void vnc_lock_queue(VncJobQueue *queue)
72 {
73 qemu_mutex_lock(&queue->mutex);
74 }
75
76 static void vnc_unlock_queue(VncJobQueue *queue)
77 {
78 qemu_mutex_unlock(&queue->mutex);
79 }
80
81 VncJob *vnc_job_new(VncState *vs)
82 {
83 VncJob *job = g_new0(VncJob, 1);
84
85 assert(vs->magic == VNC_MAGIC);
86 job->vs = vs;
87 vnc_lock_queue(queue);
88 QLIST_INIT(&job->rectangles);
89 vnc_unlock_queue(queue);
90 return job;
91 }
92
93 int vnc_job_add_rect(VncJob *job, int x, int y, int w, int h)
94 {
95 VncRectEntry *entry = g_new0(VncRectEntry, 1);
96
97 entry->rect.x = x;
98 entry->rect.y = y;
99 entry->rect.w = w;
100 entry->rect.h = h;
101
102 vnc_lock_queue(queue);
103 QLIST_INSERT_HEAD(&job->rectangles, entry, next);
104 vnc_unlock_queue(queue);
105 return 1;
106 }
107
108 void vnc_job_push(VncJob *job)
109 {
110 vnc_lock_queue(queue);
111 if (queue->exit || QLIST_EMPTY(&job->rectangles)) {
112 g_free(job);
113 } else {
114 QTAILQ_INSERT_TAIL(&queue->jobs, job, next);
115 qemu_cond_broadcast(&queue->cond);
116 }
117 vnc_unlock_queue(queue);
118 }
119
120 static bool vnc_has_job_locked(VncState *vs)
121 {
122 VncJob *job;
123
124 QTAILQ_FOREACH(job, &queue->jobs, next) {
125 if (job->vs == vs || !vs) {
126 return true;
127 }
128 }
129 return false;
130 }
131
132 void vnc_jobs_join(VncState *vs)
133 {
134 vnc_lock_queue(queue);
135 while (vnc_has_job_locked(vs)) {
136 qemu_cond_wait(&queue->cond, &queue->mutex);
137 }
138 vnc_unlock_queue(queue);
139 vnc_jobs_consume_buffer(vs);
140 }
141
142 void vnc_jobs_consume_buffer(VncState *vs)
143 {
144 bool flush;
145
146 vnc_lock_output(vs);
147 if (vs->jobs_buffer.offset) {
148 if (vs->ioc != NULL && buffer_empty(&vs->output)) {
149 if (vs->ioc_tag) {
150 g_source_remove(vs->ioc_tag);
151 }
152 if (vs->disconnecting == FALSE) {
153 vs->ioc_tag = qio_channel_add_watch(
154 vs->ioc, G_IO_IN | G_IO_OUT, vnc_client_io, vs, NULL);
155 }
156 }
157 buffer_move(&vs->output, &vs->jobs_buffer);
158
159 if (vs->job_update == VNC_STATE_UPDATE_FORCE) {
160 vs->force_update_offset = vs->output.offset;
161 }
162 vs->job_update = VNC_STATE_UPDATE_NONE;
163 }
164 flush = vs->ioc != NULL && vs->abort != true;
165 vnc_unlock_output(vs);
166
167 if (flush) {
168 vnc_flush(vs);
169 }
170 }
171
172 /*
173 * Copy data for local use
174 */
175 static void vnc_async_encoding_start(VncState *orig, VncState *local)
176 {
177 buffer_init(&local->output, "vnc-worker-output");
178 local->sioc = NULL; /* Don't do any network work on this thread */
179 local->ioc = NULL; /* Don't do any network work on this thread */
180
181 local->vnc_encoding = orig->vnc_encoding;
182 local->features = orig->features;
183 local->vd = orig->vd;
184 local->lossy_rect = orig->lossy_rect;
185 local->write_pixels = orig->write_pixels;
186 local->client_pf = orig->client_pf;
187 local->client_be = orig->client_be;
188 local->tight = orig->tight;
189 local->zlib = orig->zlib;
190 local->hextile = orig->hextile;
191 local->zrle = orig->zrle;
192 }
193
194 static void vnc_async_encoding_end(VncState *orig, VncState *local)
195 {
196 buffer_free(&local->output);
197 orig->tight = local->tight;
198 orig->zlib = local->zlib;
199 orig->hextile = local->hextile;
200 orig->zrle = local->zrle;
201 orig->lossy_rect = local->lossy_rect;
202 }
203
204 static int vnc_worker_thread_loop(VncJobQueue *queue)
205 {
206 VncJob *job;
207 VncRectEntry *entry, *tmp;
208 VncState vs = {};
209 int n_rectangles;
210 int saved_offset;
211
212 vnc_lock_queue(queue);
213 while (QTAILQ_EMPTY(&queue->jobs) && !queue->exit) {
214 qemu_cond_wait(&queue->cond, &queue->mutex);
215 }
216 /* Here job can only be NULL if queue->exit is true */
217 job = QTAILQ_FIRST(&queue->jobs);
218 vnc_unlock_queue(queue);
219 assert(job->vs->magic == VNC_MAGIC);
220
221 if (queue->exit) {
222 return -1;
223 }
224
225 vnc_lock_output(job->vs);
226 if (job->vs->ioc == NULL || job->vs->abort == true) {
227 vnc_unlock_output(job->vs);
228 goto disconnected;
229 }
230 if (buffer_empty(&job->vs->output)) {
231 /*
232 * Looks like a NOP as it obviously moves no data. But it
233 * moves the empty buffer, so we don't have to malloc a new
234 * one for vs.output
235 */
236 buffer_move_empty(&vs.output, &job->vs->output);
237 }
238 vnc_unlock_output(job->vs);
239
240 /* Make a local copy of vs and switch output buffers */
241 vnc_async_encoding_start(job->vs, &vs);
242 vs.magic = VNC_MAGIC;
243
244 /* Start sending rectangles */
245 n_rectangles = 0;
246 vnc_write_u8(&vs, VNC_MSG_SERVER_FRAMEBUFFER_UPDATE);
247 vnc_write_u8(&vs, 0);
248 saved_offset = vs.output.offset;
249 vnc_write_u16(&vs, 0);
250
251 vnc_lock_display(job->vs->vd);
252 QLIST_FOREACH_SAFE(entry, &job->rectangles, next, tmp) {
253 int n;
254
255 if (job->vs->ioc == NULL) {
256 vnc_unlock_display(job->vs->vd);
257 /* Copy persistent encoding data */
258 vnc_async_encoding_end(job->vs, &vs);
259 goto disconnected;
260 }
261
262 n = vnc_send_framebuffer_update(&vs, entry->rect.x, entry->rect.y,
263 entry->rect.w, entry->rect.h);
264
265 if (n >= 0) {
266 n_rectangles += n;
267 }
268 g_free(entry);
269 }
270 vnc_unlock_display(job->vs->vd);
271
272 /* Put n_rectangles at the beginning of the message */
273 vs.output.buffer[saved_offset] = (n_rectangles >> 8) & 0xFF;
274 vs.output.buffer[saved_offset + 1] = n_rectangles & 0xFF;
275
276 vnc_lock_output(job->vs);
277 if (job->vs->ioc != NULL) {
278 buffer_move(&job->vs->jobs_buffer, &vs.output);
279 /* Copy persistent encoding data */
280 vnc_async_encoding_end(job->vs, &vs);
281
282 qemu_bh_schedule(job->vs->bh);
283 } else {
284 buffer_reset(&vs.output);
285 /* Copy persistent encoding data */
286 vnc_async_encoding_end(job->vs, &vs);
287 }
288 vnc_unlock_output(job->vs);
289
290 disconnected:
291 vnc_lock_queue(queue);
292 QTAILQ_REMOVE(&queue->jobs, job, next);
293 vnc_unlock_queue(queue);
294 qemu_cond_broadcast(&queue->cond);
295 g_free(job);
296 vs.magic = 0;
297 return 0;
298 }
299
300 static VncJobQueue *vnc_queue_init(void)
301 {
302 VncJobQueue *queue = g_new0(VncJobQueue, 1);
303
304 qemu_cond_init(&queue->cond);
305 qemu_mutex_init(&queue->mutex);
306 QTAILQ_INIT(&queue->jobs);
307 return queue;
308 }
309
310 static void vnc_queue_clear(VncJobQueue *q)
311 {
312 qemu_cond_destroy(&queue->cond);
313 qemu_mutex_destroy(&queue->mutex);
314 g_free(q);
315 queue = NULL; /* Unset global queue */
316 }
317
318 static void *vnc_worker_thread(void *arg)
319 {
320 VncJobQueue *queue = arg;
321
322 qemu_thread_get_self(&queue->thread);
323
324 while (!vnc_worker_thread_loop(queue)) ;
325 vnc_queue_clear(queue);
326 return NULL;
327 }
328
329 static bool vnc_worker_thread_running(void)
330 {
331 return queue; /* Check global queue */
332 }
333
334 void vnc_start_worker_thread(void)
335 {
336 VncJobQueue *q;
337
338 if (vnc_worker_thread_running())
339 return ;
340
341 q = vnc_queue_init();
342 qemu_thread_create(&q->thread, "vnc_worker", vnc_worker_thread, q,
343 QEMU_THREAD_DETACHED);
344 queue = q; /* Set global queue */
345 }